2017: Pre-debut San was introduced as a member of the pre-debut group
KQ Fellaz alongside seven others, who now all are members of Ateez.
2018–present: Debut and activities with Ateez While San debuted with Ateez on October 24, 2018 as the group's lead vocalist, he is now also known as and referred to as one of the main dancers of the group. San has contributed to Ateez's discography and choreography. In 2023, he co-wrote the song "It's You" with bandmates Wooyoung and Yeosang which appeared on the album
The World EP.Fin: Will. In July 2025, his first solo song, "Creep", which he co-wrote, was released as part of the album
Golden Hour: Part.3 'In Your Fantasy Edition.
2021–present: Actor debut and solo projects In 2021, San made his acting debut in the web series "
Imitation" with bandmates Seonghwa, Yunho, and Jongho; this marked his first acting role. Between 2023 and 2024, San released song covers and a performance video. San's song "Snowflake" is an original track that highlights his vocal abilities. He has performed covers of "
Breathe" originally by
Lee Hi and "
Dear Name" originally by
IU, which he performed as a duet with bandmate Jongho. In November 2024, San appeared in the music talk show
Lee Mujin Service where he delivered live vocal performances. In June 2025, San made his first solo appearance on a talk-centered entertainment show on the show Naraesik, hosted by
Park Na-Rae. Later in the month, San was invited to a
Tag Heuer gala event in Seoul. In July 2025, San released his first ever official song "Creep" which featured in the album
Golden Hour: Part.3 'In Your Fantasy Edition'. In December 2025, San appeared as a presenter for the 'Best Teamwork Award' along with
Forestella's Go Woo-rim at the 2025
KBS Entertainment Awards. In February 2026, San appeared on the South Korean variety show
Boss in the Mirror as a Special MC.
Choreography Contributions In 2023, San's "Warriors" performance video, which he co-developed and co-choreographed, received praise from
OSEN for its "diverse choreography composition" and from
Single List for San's "detailed facial expressions that matched the mood of the song". In 2024, San was credited with contributing to the choreography for the title track "Work" from the album
Golden Hour: Part.1. In 2026, it was announced that San participated in the choreography for the title track "Adrenaline" from the album Golden Hour: Part. 4. Hongjoong said, "San was involved throughout the choreography, which is how it came together". San explained, "To express 'Adrenaline' instinctively, I focused on movements that feel like blood rushing through your body, like tightening the neck or showing blood flowing". == Other ventures ==